| XXX | (434-(Astronomy)) | XXX |
( 434 )
ASTRONOMY.
ASTRONOMY is the ſcience which treats of the nature and properties of the heavenly bodies.
Chap. I. Of Astronomy in general.
By aſtronomy we diſcover that the earth is at ſo great a diſtance from the ſun, that if ſeen from thence it would appear no bigger than a point, although its circumference is known to be 25,020 miles. Yet that diſtance is ſo ſmall, compared with the earth's diſtance from the fixed ſtars, that if the orbit in which the earth moves round the ſun were ſolid, and ſeen from the neareſt ſtar, it would likewiſe appear no bigger than a point, although it is at leaſt 162 millions of miles in diameter. For the earth, in going round the ſun, is 162 millions of miles nearer to ſome of the ſtars at one time of the year than at another; and yet their apparent magnitudes, ſituations, and diſtances from one another ſtill remain the ſame; and a teleſcope which magnifies above 200 times does not ſenſibly magnify them; which proves them to be at leaſt 400 thouſands times farther from us than we are from the ſun.
It is not to be imagined that all the ſtars are placed in one concave ſurface, ſo as to be equally diſtant from us; but that they are ſcattered at immenſe diſtances from one another through unlimited ſpace. So that there may be as great a diſtance between any two neighboring ſtars, as between our ſun and thoſe which are neareſt to him. Therefore an obſerver, who is neareſt any fixed ſtar, will look upon it alone as a real ſun; and consider the reſt as ſo many ſhining points, placed at equal distances from him in the firmament.
By the help of teleſcopes we diſcover thouſands of ſtars which are inviſible to the naked eye; and the better our glaſſes are, ſtill the more become viſible; ſo that no limits can be ſet either to their number or their diſtances.
The ſun appears very bright and large in compariſon of the fixed ſtars, becauſe we keep conſtantly near the ſun, in compariſon of our immenſe diſtance from the ſtars. For a ſpectator, placed as near to any ſtar as we are to the ſun, would ſee that ſtar a body as large and bright as the ſun appears to us : and a ſpectator, as far diſtant from the ſun as we are from the ſtars, would ſee the ſun as ſmall as we ſee a ſtar, diveſted of all its circumvolving planets; and would reckon it one of the ſtars in numbring them.
The ſtars, being at ſuch immenſe diſtances from the ſun, cannot poſſibly receive from him so ſtrong a light as they ſeem to have : nor any brightneſs ſufficient to make them viſible to us. For the ſun's rays muſt be ſo ſcattered and diſſipated before they reach ſuch remote objects, that they can never be tranſmitted back to our eyes, ſo as to render theſe objects viſible by reflexion. The ſtars therefore ſhine with their own native and unborrowed luſtre, as the ſun does; and ſince each particular ſtar, as well as the ſun, is confined to a particular portion of ſpace, it is plain that the ſtars are of the ſame nature with the ſun.
It is noways probable that the Almighty, who always acts with infinite wiſdom, and does nothing in vain, ſhould create ſo many glorious ſuns, fit for ſo many important purpoſes, and place them at ſuch diſtances from one another, without proper objects near enough to be benefited by their influences. Whoever imagines they were created only to give a faint glimmering light to the inhabitants of this globe, muſt have a very ſuperficial knowledge of aſtronomy, and a mean opinion of the Divine Wiſdom : ſince, by an infinitely leſs exertion of creating power, the Deity could have given our earth much more light by one ſingle additional moon.
Instead then of one ſun and one world only in the univerſe, aſtronomy diſcovers to us ſuch an inconceivable number of ſuns, ſyſtems, and worlds, diſperſed through boundleſs ſpace, that if our ſun, with all the planets, moons, and comets belonging to it, were annihilated, they would be no more miſſed, by an eye that could take in the whole creation, than a grain of ſand from the ſea-ſhore: The ſpace they poſſeſs being comparatively ſo ſmall, that it would ſcarce be a ſenſible blank in the univerſe, although Saturn, the outermoſt of our planets, revolves about the ſun in an orbit of 4884 millions of miles in circumference, and ſome of our comets make excurſions upwards of ten thouſand millions of miles beyond Saturn's orbit; and yet, at that amazing diſtance, they are incomparably nearer to the ſun than to any of the ſtars; as is evident from their keeping clear of the attractive power of all the ſtars, and returning periodically by virtue of the ſun's attraction.
From what we know of our own ſyſtem, it may be reaſonably concluded, that all the reſt are with equal wiſdom contrieved, ſituated, and provided with accommodations for rational inhabitants. Let us therefore take a ſurvey of the ſyſtem to which we belong; the only one acceſſible to us; and from thence we ſhall be the better enabled to judge of the nature and end of the other ſyſtems of the univerſe. For although there is almoſt an infinite variety in the parts of the creation which we have opportunites of examining; yet there is a general analogy running through, and connecting all the parts into one great and universal ſyſtem.
To an attentive conſiderer, it will appear highly probable, that the planets of our ſyſtem, together with their attendants called ſatellites or moons, are much of the
